Unit Tests vs. Acceptance Tests

Question

Are you for one or the other? Or both?

My understanding is unit tests:

• validate the system from the developer\'s point of view
• help developers pr

Answer 1

Unit Tests - my specific function does what it's supposed to do, nothing more, and nothing less.

Acceptance Test - my application does what it's supposed to do.

Example: Application to calculate roots of quadratic functions. Takes inputs of a, b, and c, returns roots x1 and x2. This application is built by functions I write to add two numbers, subtract two numbers, multiply two numbers, divide two numbers, and take the square root of two numbers.

Unit tests - check that my divide and multiply functions work correctly, my square root works correctly, my add and subtract work correctly.

Acceptance tests - check that my application calculates roots of quadratic functions.

Since my entire application is to calculate roots, I should not have a unit test that also calculates roots because there is no individual function which does so.